Sucralose (4,1′,6′-trichloro-4,1′,6′-trideoxygalactosucrose), a high-intensity sweetener that can be used in many food and beverage applications, is a galacto-sucrose having the following molecular structure:

Sucralose is made from sucrose by converting the hydroxyls in the 4, 1′, and 6′ positions to chloro groups. In this process, the stereochemical configuration at the 4 position is inverted.
In one process for making sucralose from sucrose, sucrose is first converted to a sucrose-6-ester, such as sucrose-6-acetate or sucrose-6-benzoate. The sucrose-6-ester is chlorinated by reaction with a chlorination agent and a tertiary amide, and the resulting reaction mixture heated and then quenched with aqueous alkali. The resulting 4,1′,6′-trichloro-4,1′,6′-trideoxygalactosucrose ester (sucralose-6-ester) is converted to sucralose, which is subsequently purified and isolated.
This process typically provides a product that contains varying amounts of other chlorinated sugar compounds in addition to sucralose. During removal of these impurities the loss of sucralose should be minimized, and the purification and isolation process should be economical to operate on a large scale. Although advances have been made in the purification of sucralose, there is a continuing need for processes that remove impurities from sucralose, produce sucralose in high purity, minimize the yield loss in the purification process, and are economical to operate on a large scale.